Relay.



M. HARTENHEIM.

RELAY. 4

V I APPHCATION FILED AUG. 10, I915- 1,227,433. Patented May22,19 I z'snsns-snnzr Q Q L Q.

WITNESSES: INV'ENTOR i BY AT'I'ORNEY/ UNITED STATES PATENT OFFICE.

MAX KARTENHEIM, O F PITTSBURGH, PENNSYLVANIA, ASSIGNOB TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

NELLY.

Specification of Letters Patent.

Patented May 22, 1917.

Application filed, August 10, 1915. Serial m. 44,743

To all whom it may concern:

Be it known that I, MAX Haarnxnnrar, a subject of the German Empire, and aresident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Relays, of which the following is a specifi cation. l

My invention relates to relays and particularly to hot-wire'relays that are utilized for controlling the operation of dynamoelectric machines. v

One object of my invention is to provide a relay of the above indicated character that operates to effect engagement of its contact members .when the current traversingthe relay is decreasing and of apredeterm'ined value.

Another object of my invention is to provide a relay that will operate to efl'ect engagement .of its contact members when a redetermined current traverses; the same or a predetermined time.

:Inthe starting of dynamo-electric machines asmotors, it is desirable tovinsert a resistor in series with the armature thereof to limit the amount of'current that flows when the circuit. is first closed. This current rises 'to'a maximum value and then de-' creases when the counter electromotive force gradually builds up, and, when'it has decreased to a. predetermined value, the resistor is usually short-circuited. If'an ordinary relay is usedior controlling the shortcircuiting oflthe resistor, it will operate when the current reaches a predetermined value while ascending Since this do'e's not permit the -motor to accelerate properly before theresistoris short-circuited, I provide a -relay that automatically controls the short-circuiti-ng of the resistor when the accelerating current is decreasing and' of a predetermined .value.

a I further provide means whereby the refor interruptin set forth finay be utilized the circuit of the motor it a predetermine load traverses the same for a predetermined time.

' Fi ure 1 of the accompanymgdrawings is a iagrammatic view of arel'ay embodying my invention, Fig. 2 1s a 1 dm am; illustrating the starting current of a ynamo-electric machine, .and F1 3 1s a diagrammat'c view of a modifie form of a relay hereinbefore lay embodying my invent-ionr '-The rela 7 comprises "we ne'eted, at their res minals 6 and 8.

In Fig. 1 ofthe'drawin an electric circuit 1, comprising two con uctors 2 and 8, is

provi'ded forsupplying a motor 4 with current. A res1stor'5 is so conn'ected-to the armature of the motor 4 that, when the same is started, the rush of-current that traverses the. armature is limited until the'motor has accelerated a ,sufiicient amount. The resistor 5 is connected, at one terminal,

to one terminal of the armature of the motor 4, and at its other terminal, to one terminal 6 of'a relay 7'. The other terminal 8 of the' relay 7 is connected-to the conductor 3. A conductor 9 ,is-also connected to the terminal 8 and to astationauyfcontact member 10.. A ;conductor.11' is connected to a stationary contact member 12 and also to one terminal of the resistor so" as to provide a short-circuit path f,or,.the

cur'rent traversing the -armature of jrthe motor 4 when it isdesirable thatthere- "sistor 5 and-relay 7 be from the circuit.

nect'ed con uctors113 and 14 at-arecon o arinslli'and 16 are ivotally mounted upon stationary memsham 've end to the .ter-

rs 17 and 18, respectively. Contact inembars 19" and 20 are mounted .at-the respective ends of the. arms 15 and 16 andare adapted to engage stationary contact mem- 'ductors.13 and 14 are maintained .under tension by means of two connectors. 0 1 2 1118 23 is connected, the cord 23. to the mid point 24: of the con uctor 14 and also to one "end of the-spring- 25, the othere'nd of .which is connected to a stationarymember 2'6. Likewise, the arm16 is connected, by the cord 27, to the mid point 28- ofthe conductor 13 and alsoztorone end ofthe spring 29, the other end of which. is' c0nnected to a .stationary member .30. .The springs 25 a and 29 are so adjusted. that the contact members 19 and..21 are; normally in enga ment when no current traverses the con uctors 13 and-:14, and the-contact me'm'be'rs'20 and 22 are normally out of en agement when no 'J the relay. 32, the other of w 'ch is connected to the conductor 2., The relay, 82

' here 21 and .22, respectively; The twoconand 27 and's rings 25 and 29; 'The arm 15 l comprises amovable core member '33; two' movablecontact members tA and 36 and arestrammg spring 35'. .The stationary contact member 22 is connected to the-conduc- \Vh'en cu1'rent."traverses -'the circuit a rush of current traversesthe armature of the motor =1. the resistor 5 and'the" conductors. 13 and 14; The contact 1i1embers=19 and 21, on" account of the substantially instantaneous heatin oi the conductor 14. quickly -separate w iile the contactmember 20 slowly approaches engagement with the zg contact member 22.- After the current has reached its ma'ximnin value. it begins-to de-. crease, -and the conductor l-L contracts. 'while the conductor '13 is still eicpanded .sufli ci'ently to maintain the contact members 20 -3 and 22 inengagement. "Thus. the contact members 19 and 21 are again engaged. while the contact members 20 and 22 are stillens gaged to thus complete the circuit throu h the winding-'31- o fthe relay 32, causing t me movable contact member 3-1 to" engage the 's'tationary' contact-- members 10 and 12. whereby the current that traverses the armature of the'motor 1L is permitted to travelse the conductors 9 and 11 to thus short a0 circuit 'the resistor 5 and the relayT.

conductor 38 is.connectedto onefter minal. of the' winding 31 and to a stationary contact member A conductor -10 is con-- nected to the corresponding stationary. con- 4'3 tact member 11 and to 'the stationary contact member This connection is pro-' vided so. that. when the relay 32'operates. themovable contact member 36 engagesthe contact members 39 and. 41 to thus maintain the relay 3:2 in operative relation when the conductors 13 and 11 contractto disengage .the contact lHQlHl'JlS 20 and after the relav 7- has been short-circuited.

It will be seen from the above description that the currenttraversing the armature of the motor 1 follows substantially the curve shown in Fig. 2. wherein the line 37 represents the value of the current for which the relav 7 adjusted. The point 38 indicates the point at which the contact members are simultaneously in engagement. Although the point- 39 indicates the same value-8i current asthe point the relay 31 511- n' o t be actuated atthe point 39 because tli ei con tact members are only simultaneously enprefietrmihed value:

gaged when thecurrentis'decreasing and of a predetermined value.-

. In Fig. 3 of the-drawings the relay 31 is. adapted to short-circuit the resistor 5. only, and a stationary contact member 42 is adapted to be engaged by the movable conf'tact member 19 under predetermined "conditions. A circuit ihterrupter-l3,- having a trip coil -14. .is connected in circuit with the motor 4. and-the trip coil 14; is-conhected to the conductorv 2 and to-the contact mem-' her *2. I i

1 Upon starting the motor 4, the relay 7 operates-when the current is decreasing and of a predetermined value to short-circuit the resistor 5 only. If. howev r; an esicess cur rentagai'n traverses the "indings of the motor t and persists-for a ime that issuflicient to cause the conductor 1% to expand again, the'contact member 19 will engage the contactmember 42 to thereby trip the circuit interrtipterfi, thus providing ample pro ection against overloads as well as means for automatically short-circuiting the starting resistor. I

If the potential of the circuit 1 is reduced to a predetermined value. the winding 31 will 'be s-uflicie'ntly deenergized to permit the spring 35 to open the short-circuit path around the resistor 5 to thus prevent the 5 motor from being injured .when the potential is again raised. 1 I

'hile I have described my invention with respect to a particulardirect-current application, it-will be understood that I do not 10 limit'my invention tothatparticular aplicatioii or to 'the particular construction lllustrated. as many modificationsinay be made thereinwithout departing from the spirit and sec )e of the invention as set forth 1n the a-ppen ed claims.

I claim as my im'ention:

.' '1. A relay comprising two thermal-re sponsivemembers adapted to be heated equallya-nd to have different thermal inertia. contact devices adapted to be actuated. by the movement of the said thermalresponsive members, one of said contactdevices being adapted to be normally open and the other to be normally closed.

2. A relay for an electric circuit comprising two conductors, stationary contact members. and movable contact members adaptedto be actuated bythe expansion and contraction of the conductors when-currents trav- 'ers'e the same. the time of expansion and contraction of one of the conductors being 50 difl'erent from thatof the otherthat the contactmembersare adapted to be engaged simultaneously only. when the current-trav- 12a ersingthe conductors is decreasing an ofia' 3Z, A'Y'rela comprisin two parallelc nected-I. con uctors of ifierent cross tional;.-areas',' stationary contact member 13 0 and movable contact members operatively connected to the parallel-connected conductors, the con-tact member that is. connected to the conductor having the smaller cross sectional area being normally in engagement with its stationary contactrmember and the other contact membersb'e'ing normally disengaged, the first-mentioned contact member being adapted to operate relatively more quickly than the other contact member.

4. A relay comprising two conductors having relatively different cross-sectional areas, contact devices adapted to be actuated by the expansion and contraction of thecon ductors, the contact device that is actuated by the conductor having the smaller crosssectional area bein normally closed and the other being norina ly open.

5. A relay comprising two conductors having different thermal inertia, a normally open contact device adapted to be actuated by the movement of one conductor when current traverses the same, and a normally closed contactjdevice adapted to be actuated by the movement of theother conductor when current traverses the same, the rela' tive movements of the said conductors, when traversed by equal currents, being such that the contact devices are simultaneousl closed only when .the current traversing t econductors is a predetermined value and decreasing.

' 6. A relay for an electric circuit comprising two conductors having different thermal inertia, a normally open contact device adaptedto be actuated bythe' relatively quick-responding conductor and a normally closed contact device adapted to be actuated by the relatively slowresponding conductor..

7. A relay comprising two conductors having substantially different thermal inera plurality of stationary contact members tia,a plurality of movable contact members operatively connected to the conductors, and

adapted to be engaged by the movable contact-members, one pair of contact members being adapted to be engaged simultaneously only when the current traversing the conductors is of a. predetermined value and decreasing and the other pair being adapted to'be engaged only when a predetermined current traverses .the conductors for a 'predetermined time. p

8. A relay comprising two conductors having different thermal inertia, cooperating contact members operatively connected to the conductors, said conductors being adapted to expand and contract when currenttraverses the same to cause the cooperating contact members to be engaged simultaneously only when the current traversing the conductors is a predetermined value and decreasing.

9. A relay comprising two thermal-responsive members, cooperating contact members actuated thereby,'said responsive membershaving such thermal inertia that the contact members areadapted to be engaged simultaneously only under predetermined conditions.

10. A relay comprising two thermal-responsive members, cooperating contact members actuated thereby, said responsive members having such thermal inertia that the contact members are adapted to'be engaged simultaneously only when the responsive members have been heated a predetermined amount and the amount of heating is being reduced.

11. In an electric circuit, the combination with two expansible-conductors adapted to have different thermal inertia, of a normally closed contact device actuated by the movement of one conductor, and a normally open contact device actuated bythe movement of the other conductor, the difference in thermal inertia of the said conductors being-such that the contact-devices are simultaneously vices, said responsive devices being adapted toso actuate the'contact' members that they are engaged and disengaged under predetermined conditions in the circuit. 13. In an electrlc circuit, the combination a with twothermal-resp'onsive devices responsive in difierent degrees 'to current traversing the circuit, of contact members actuated bythe movement of'th'efsaid responsive devices, said .responsive'devices being adapted 'to so actuate the contact members that they are engaged simultaneously only when the current traversing the. circuit is decreasing.

14. In an electric circuit, the combination with two thermal-responsive devices responsive in different degrees to current traversing the circuit, of contact members actuated by the 'movementof the said responsive devices, said responsive devicesfbeing adapted to so actuate. the contact members that they are engaged simultaneously only when thecurrent traversing thecircuit has decreased to a predetermined value.

In testimony whereof, I have hereunto subscribed my name this 6th day of August, 1915.

MAX HARTENHEIM. 

